High draft mechanism with endless belts



Je 9, 1936. F. cAsABLANcAs HIGH DRAFT MECHANISM WITH ENDLESS BELTS Filed May 3, 1934 2 Sheets-Sheet l Ilm lx n bj- Invenr' Fernando Cwalzmda @Marr-n.055'.

1M y. W6 F. CASABLANCAS HIGH DRAFT MECHANISMWITH ENDLESS BELTS Filed May 3, 1934 2 Sheets-Sheet 2 Patented `lune 9, 1936 UNITED STATES HIGH DRAFT MECHANISM WITH ENDLESS BELTS Fernando Casablancas, Sabadell, Spain Application May 3, 1934,` Serial No. '723,791 In Spain May 26, 1933 3 Claims.

In high draft mechanisms with endless belts for textile rovings, it is of great importance to ensure an exact and regular movement of the belts, thus avoiding any deviation thereof. In

.5 those cases in which the belts are of comparatively small width, such as are usually employed in ring spinning frames, in general the action of the framework or cage which guides the belts laterally is sufficient to ensure that these work propifi erly without deviation. On the contrary, where very wide belts are used, as takes place in drawing frames, flyer frames and in some types of self-acting machines, the effect of the guiding framework is not sufficient to ensure a goed guid- `=5 ance of the belts and to prevent absolutely the deviation or displacement thereof.

In these cases, owing to the great width of the belt as also by reason of the inequalities of thick-` ness and consistency which the material thereof inevitably presents, it is very difficult for the belt to be perfect, and to have the same peripheral length throughout the whole of its width. Furthermore, and owing to the slight transverse rigidity of the belt, also due to its width, on one of its edges rubbing against one of the lateral faces of the guiding framework the movement of this edge is retarded and in either case the belt does not run true, that is to say, it runs obliquely with respect to the tangential line of the two cylinders which actuate it, and forms a small wrinkle on the edge which rubs, and this increases owing to the operation of the belt until a moment is reached at which this wrinkle is caught between the two cylinders and the belt is torn.

5 ,5 This takes place all the more, the more the cylinders actuating the belts are loaded, since this load, due to the slight inequalities of the material of the belt which cannot be absolutely homogeneous over the whole of its width, produces an unequal draft of the belt in the longitudinal sense which increases the above-mentioned effects. Furthermore, in thosemechanisms in which the belts operate at a relatively high speed such as takes place in some cases with drawing frames, this velocity again accentuates these defects.

To avoid this irregular operation of the belts, it has been proposed to diminish as far as Vpossible the pressure which the cylinders exert between themselves and upon the belts, but as in the event of diminishing this pressure there is easily produced a slipping of the cylinders and consequently an irregular movement of the belts, it has been necessary in these cases to t gears to the lower and upper cylinders to ensure that the movement is transmitted without slip from the lower cylinder to the upper one. The fitting of these gears complicates to a large extent the construction and operation of the drawing mechanisms.

My invention entirely avoids any lateral deviation of the belt and ensures the regular operation of the mechanism without the necessity of diminishing the pressure which the cylinders exert between themselves, and consequently without the necessity cf fitting gearings to the cylinders.

The invention consists essentially in arranging either on the lower cylinder or on the upper cylinder of each pair or in both simultaneously, retracted parts which do not extend over the whole length of the cylinder, in such a manner that the surface of this cylinder is discontinuous in a portion which does not extend over the whole of its length and in this way every time this retracted part of the cylinder passes through the tangential line of the two cylinders, the belt is momentarily free at one part of its width and if it has undergone any deviation it can correct itself following the guiding action of the two lateral plates of the frame.

`These retracted parts of the cylinder are arranged preferably in the form of planes or longitudinal grooves which do not extend over the whole length of the cylinder and are arranged alternately so that on each revolution of the cylinder all the parts of the width of `the belt have remained free for at least once at one moment or the other.

In this way, whatever may be the widthof the belts used in the drawing mechanism, these suitably obey the guiding action of the frame and lateral deviation is absolutely prevented without it being necessary todiminish the pressure of the cylinders.

The invention forming the object of this patent is shown on the annexed drawings.

Figure l shows diagrammatically and on a much larger scale, viewed from above, a belt with the guiding framework, in the correct operating position.

Figures 2, 3 and 4 represent the different positions which this belt takes up when it deviates or inclines laterally.

Figure 5 represents in vertical section through the line V-V of Figure 7, two pairs of adjacent cylinders of a drawing mechanism with very wide belts and to which this invention has been applied.

Figurc 6 is a section through the line Figure 5, and

VI--VI of Figure '7 is a section through the line VII-VII of Figure 5.

In these iigures, I represents the bottom cylinders of a spinning frame which have been constructed in the usual manner, forming a bar which extends over the whole length of the machine, and 2 represents the upper cylinders which also in the usual manner are connected by pairs forming a single piece. Over these cylinders I, 2 are the bel-ts 3, 4 which are guided laterally by means of the framework or cage 5.

Figures 1 to 4 represent in plan the position of the lower belt 3 presuming that the upper cylinder 2 and the upper belt 4 are removed. When the belt works under good conditions, it occupies the correct position shown in Figure 1.

When dealing with very wide belts it frequently happens that one of the edges, for example E, of the belt has a winding out slightly greater than the other edge "I, and as the belt is gripped at the tangential line VIII-VIII of the two cylinders, owing to this slightly greater winding out, the

edge 'I of the belt will be retarded and the belt will take up successively the positions shown in Figures 2, 3 and 4 until there arrives a moment in which the belt forms a comparatively large wrinkle and this wrinkle is caught by the cylinders, thus tearing the belt. The same thing takes place even when the dimensions of the belt are absolutely exact, owing to the differences of homogeneity which of necessity are always presented by the leather or other material of which the belts have been made.

This deviation of the belts makes the application of high draft mechanisms with endless belts extremely difIicult to all those machines in which each pair of belts works a comparatively large number of rovings, thus necessitating having a very great width.

Figures 5 to 7 represent the invention applied to the cylinders of a high draft mechanism. In

l the embodiment represented in these gures, the

upper cylinders 2 have flats or retracted parts II), I I arranged to follow the generatrices of the cylinder so that at these parts the belt does not touch the cylinder. Each of these retracted parts I0, II has a length less than the total length of the cylinder but they are alternated in such manner that their projections over the axis of the cylinder cover the whole length thereof. For example and asshown in the drawings, the retracted part I occupies somewhat more than the left half of the cylinder and the part II occupies somewhat more than the right half thereof. These retracted 'parts Ill, I I are furthermore displaced in the periphery of the cylinder by a certain angle which may be 180 as represented in the drawings, or of any other suitable value.

On the rotation of the cylinder 2, when this passes through the tangential line of the two cylinders, one of these retracted parts, for example the one I 0, as shown in Figures to 6, the belts3, 4 are free from pressure over the whole part corresponding to the length of this retracted part Ill, and consequently all this part of the belts can easily adjust itself in case any deviation has been initiated. Nevertheless the belts do not cease to be actuated with regularity since they remain held or retained for all the length of the cylinder1 over which the retracted part I0 does extend. Furthermore, since this retracted part I0 is narrow, the belts remain free for only a very short time so that this has no iniluence on the movement of the belts.

The part to the right of the belts which has not been free in passing the retracted part Ill, is, on the contrary, free on reaching a further half revo-lution, when it passes the other retracted part II through the tangential line of the two cylinders, in such manner that all the portions of the width of the belts are free at one moment or the other on each revolution of the cylinder.

As may be understood, the retracted parts I0, II may be given other shapes than those shown and may also be of greater number or arranged in other positions. The only requirement is that each of the retracted parts in itself is of a length less than the total length of the cylinder and that these retracted parts are alternated in such a manner that the total length of the cylinder is comprised between the retracted parts so that all the portions of the width of the belts are free from pressure at one moment or the other on each revolution of the cylinders.

I claim:-

1. In a drawing mechanism for textile rovings having endless belts for conducting the rovings, contacting cylinders for engaging said belts, one of said cylinders cut inwardly from opposite ends and opposite sides along the outer surface to form diametrically opposed retracted portions with their inner ends extending slightly beyond one another, the said retracted portions normally being free of contact with the belt engaging said cylinder, and means for rotatably supporting said cylinders to drive the belts, whereby said retracted portions upon said cylinder permit the belts to automatically adjust themselves laterally.

2. In a drawing mechanism for textile rovings having endless belts for conducting the rovings, contacting cylinders for engaging said belts, one of said cylinders cut axially along the outer surface from opposite ends and opposite sides to form diametrically opposed retracted portions, each of said retracted portions having a at surface extending substantially half of the length of the cylinder and normally being free of contact with the belt engaging said cylinder, and means for rotatably supporting said cylinders to drive the belts, whereby said retracted portions upon said cylinder permit the belts to automatically adjust themselves laterally.

3. In a drawing mechanism for textile rovings having endless belts for conducting the rovings,

contacting cylinders for engaging said belts, one of said cylinders having flat portions upon its outer surface disposed diametrically to one another, each of the said flat portions extending inwardly from the opposite ends of the cylinder part of the length thereof to provide non-contacting portions upon the belt with the cylinder when nor- Ymally passing the belt between said contacting cylinders, and means for rotatably supporting said cylinders to drive said belts, whereby said non-contacting portions upon said cylinder permit the belts to automatically adjust themselves laterally.

FERNANDO CASABLANCAS. 

